Optimization of ciprofloxacin degradation in wastewater by homogeneous sono-Fenton process at high frequency

Abstract

Emerging pollutants such as pharmaceuticals have been focusing international attention for a few decades. Ciprofloxacin (CIP) is a common drug that is widely found in hospital and wastewater treatment plants effluents, as well as in rivers. In this work, the feasibility of CIP degradation by ultrasound process at high frequency is discussed and sonolysis, sonolysis with hydrogen peroxide and sono-Fenton are evaluated. The amounts of hydrogen peroxide and ferrous ions (Fe²⁺) needed were optimized using response surface methodology. Best results were obtained with the sono-Fenton process resulting in a total pharmaceutical degradation within 15 min and a mineralization greater than 60% after 1 h. Optimal conditions were tested on a real matrix from a municipal wastewater treatment plant. Even if the degradation of the pollutants by sono-Fenton was hampered, the removal efficiency of both CIP and total organic carbon (TOC) is interesting as an increase in the biodegradability of the wastewater is found. These results show that sono-Fenton oxidation can be a promising pretreatment process for pharmaceutical-containing wastewaters.

Keywords:

• Advanced oxidation processes
• pharmaceuticals
• optimization
• sono-Fenton
• ultrasound
• wastewater treatment

Acknowledgments

The authors would also like to express their gratitude to the Collaboration Services of the French Embassy in Cuba for the financial support and to the Laboratory of Environmental Analysis of InSTEC-University of Havana for the analytical support of wastewaters.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the project TATARCOP of Instituto Superior de Tecnologías y Ciencias Aplicadas (InSTEC)-University of Havana.